1. Field of Invention
The present invention relates to an inductor structure. More particularly, the present invention relates to a radio frequency (RF) semiconductor inductor with less substrate loss.
2. Description of Related Art
In general, an inductor is formed over a lossless substrate such as gallium arsenic substrate or a sapphire substrate which has a promising insulation effect to result in a low induced substrate current. Therefore, a high quality of the inductor can be obtained to enable an operation under a radio frequency (RF). However, since gallium arsenic substrate or sapphire crystal is expensive, a silicon substrate is typically used to reduce the cost. Using silicon technology to fabricate the inductor on a silicon substrate, though achieve a low cost fabrication, results in a higher consumption of energy. At present, methods to overcome the problem of high energy consumption by using silicon substrate have been developed. For example, the application of local substrate removal or slotted ground plane has been disclosed. However, these methods are not very practical and the effect is restricted.